Real-Time systems are defined not only by their logical correctness but also timeliness. Modern real-time systems, such as those controlling industrial plants or the flight controller on UAVs, are no longer isolated. The same computing resources are shared with a variety of other systems and software. Further, these systems are increasingly being connected and made available over the internet with the rise of Internet of Things and the need for automation. Many real-time systems contain sensitive code and data, which not only need to be kept confidential but also need protection against unauthorized access and modification. With the cheap availability of hardware supported Trusted Execution Environments (TEE) in modern day microprocessors, securing sensitive information has become easier and more robust. However, when applied to real-time systems, the overheads of using TEEs make scheduling untenable. However, this issue can be mitigated by judiciously utilizing TEEs and capturing TEE operation peculiarities to create better scheduling policies. This thesis provides a new task model and scheduling approach, Split-TEE task model and a scheduling approach ST-EDF. It also presents simulation results for 2 previously proposed approaches to scheduling TEEs, T-EDF and CT-RM. / Master of Science / Real-Time systems are computing systems that not only maintain the traditional purpose of any computer, i.e, to be logically correct, but also timeliness, i.e, guaranteeing an output in a given amount of time. While, traditionally, real-time systems were isolated to reduce interference which could affect the timeliness, modern real-time systems are being increasingly connected to the internet. Many real-time systems, especially those used for critical applications like industrial control or military equipment, contain sensitive code or data that must not be divulged to a third party or open to modification. In such cases, it is necessary to use methods to safeguard this information, regardless of the extra processing time/resource consumption (overheads) that it may add to the system. Modern hardware support Trusted Execution Environments (TEEs), a cheap, easy and robust mechanism to secure arbitrary pieces of code and data. To effectively use TEEs in a real-time system, the scheduling policy which decides which task to run at a given time instant, must be made aware of TEEs and must be modified to take as much advantage of TEE execution while mitigating the effect of its overheads on the timeliness guarantees of the system. This thesis presents an approach to schedule TEE augmented code and simulation results of two previously proposed approaches.

The primary issue with developing new networking protocols is testing how the protocol will behave when deployed on a large scale; of particular interest is how it will interact with existing protocols. Testing a protocol using a network simulator has drawbacks. First, the protocol must be written for the simulator and then rewritten for actual deployment. Aside from the additional work, this allows for software bugs to be introduced between testing and implementation. More importantly, there are correctness issues. Since both the new and existing protocols must be specially written for the simulator, and not actual real-world implementations, the question remains if the behavior observed and, specifically, the interactions between the protocols are valid. Direct code execution environments solve the correctness problem, but there is the loss of control that a simulator provides. Our solution is to create an environment that allows direct code execution to occur on top of a network simulator. This thesis presents the primary component of that solution: Lunar (Linux User-level Network Architecture), a user-level library that is created from the network stack portion of the Linux operating system. This allows real-world applications to link against a simulator, with Lunar serving as the bridge. For this work, an implementation of Lunar was constructed using the 2.4.3 version of the Linux kernel. Verification testing was performed to demonstrate correct functioning of the library using both TCP (including TCP with loss) and UDP. Performance testing was done to measure the overhead that Lunar adds to a running application. Overhead was measured as the percent increase in the runtime of an application with Lunar as compared to the application running without it, and ranged from approximately 2% (running over 100 Mbps switched Ethernet) to approximately 39% (1 Gbps Myrinet). / Master of Science

Yes / This paper presents a re-evaluation of a cemetery excavated over thirty years ago at Walkington Wold in east Yorkshire. The cemetery is characterised by careless burial on diverse alignments, and by the fact that most of the skeletons did not have associated crania. The cemetery has been variously described as being the result of an early post-Roman massacre, as providing evidence for a `Celtic¿ head cult or as an Anglo-Saxon execution cemetery. In order to resolve the matter, radiocarbon dates were acquired and a re-examination of the skeletal remains was undertaken. It was confirmed that that cemetery was an Anglo-Saxon execution cemetery, the only known example from northern England, and the site is set into its wider context in the paper.

The theme of my thesis is to compare legal regulations of two fundamental institutions used for compulsory fulfilment of obligations. It comprises the execution of a decision pursuant to Part Six of Act No. 99/1963 Coll. Civil Procedure Code, and the execution pursuant to Act No. 120/2001 Coll. On Executors and Execution Proceedings. The purpose of the thesis is to compare the fundamental legislation with emphasis on their differences and investigating the advantages and disadvantages of both procedures. This is a hot issue, particularly with regard to the forthcoming amendments to both institutions. The work focuses on the legal regulation in force, but it also offers a comparison with the amendment mentioned above, which is going through the legislative process in Parliament of the Czech Republic at the time of preparing this thesis. The thesis is divided into eleven chapters. The first chapter gives an introduction to the problems of both proceedings and presents the fundamental legal regulation and their mutual relationship. The next two chapters deal with the position of an executor in execution processes and the role of a court in the execution of both decisions and executions. Chapters four to ten deal with the individual phases in the two proceedings. It is especially the alteration to...

O sistema de execução forçada é o instrumento previsto no Código de Processo Civil Brasileiro destinado a satisfazer o credor de obrigações pecuniárias contidas em sentenças ou em títulos executivos extrajudiciais. Trata-se de sistema cujo bom funcionamento não só interessa às partes de um litígio, mas a toda sociedade, em função de suas importantes repercussões sociais e econômicas. Por meio da execução forçada o Juiz invade o patrimônio do devedor, independentemente da vontade deste, e expropria bens em benefício do credor. Para o adequado funcionamento da execução forçada é essencial que o ato processual de penhora de bens do devedor seja efetivo. A penhora consiste em apreender e afetar juridicamente bens do devedor, os quais ficam vinculados ao Juízo da execução até o momento próprio de realização da expropriação dos bens. A penhora é ato processual que incide sobre a realidade econômica e social e padece de suas contingências. O objetivo desta dissertação de Mestrado é investigar a relação entre o ato de penhora e seu objeto, a partir da premissa de que o método ou a forma de apreensão judicial deve estar plenamente adaptado aos atributos sociais, jurídicos e econômicos do bem que se pretende apreender. Nesse contexto, será investigado o regime da penhora do Código de Processo Civil Brasileiro, bem como serão estudados os tipos de penhora de bens de significação econômica mais importante na realidade atual. / The system of forced execution is the instrument set forth in the Brazilian Code of Civil Procedure destined to satisfy the creditor of pecuniary obligations contained in judgments or in extrajudicial execution instruments. It is a system, the good functioning of which is of interest not only to the parties in a litigation, but also to society as a whole, in view of its important social and economic repercussions. The Judge, by means of the forced execution, invades the debtors assets, irrespective of the will of the latter, and expropriates assets to the benefit of the creditor. For the proper functioning of the forced execution, it is essential that the procedural act of levy of the debtors assets be effective. The levy consists of seizing and legally affecting the debtors assets, which become bound to the Court of the execution until the specific time of performance of the expropriation of the assets. The levy is a procedural act which applies to economic and social reality, and lacks its contingencies. The objective of this Masters dissertation is to investigate the relationship between the act of levy and its object, starting from the premise that the method or the form of judicial seizure must be fully adapted to the social, juridical and economic attributes of the asset which is intended to be seized. In this context, the regime of levy in the Brazilian Code of Civil Procedure will be investigated, as well studying the types of levy of assets of the most important economic significance in the current reality.

Esta tese apresenta DCE, ou Execução Dinâmica Condicional, como uma alternativa para reduzir o custo da previsão incorreta de desvios. A idéia básica do modelo apresentado é buscar e executar todos os caminhos de desvios que obedecem à certas restrições no que diz respeito a complexidade e tamanho. Como resultado, tem-se um número menor de desvios sendo previstos e consequentemente um número menor de desvios previstos incorretamente. DCE busca todos os caminhos dos desvios selecionados evitando quebras no fluxo de busca quando estes desvios são buscados. Os caminhos buscados dos desvios selecionados são então executados mas somente o caminho correto é completado. Nesta tese nós propomos uma arquitetura para executar múltiplos caminhos dos desvios selecionados. A seleção dos desvios ocorre baseada no tamanho do desvio e em outras condições. A seleção de desvios simples e complexos permite a predicação dinâmica destes desvios sem a necessidade da existência de um conjunto específico de instruções nem otimizações especiais por parte do compilador. Além disso, é proposta também uma técnica para reduzir a sobrecarga gerada pela execução dos múltiplos caminhos dos desvios selecionados. O desempenho alcançado atinge níveis de até 12% quando um previsor de desvios Local é usado no DCE e um previsor Global é usado na máquina de referência. Quando ambas as máquinas empregam previsão Local, há um aumento de desempenho da ordem de 3-3.5%. / This thesis presents DCE, or Dynamic Conditional Execution, as an alternative to reduce the cost of mispredicted branches. The basic idea is to fetch all paths produced by a branch that obey certain restrictions regarding complexity and size. As a result, a smaller number of predictions is performed, and therefore, a lesser number of branches are mispredicted. DCE fetches through selected branches avoiding disruptions in the fetch flow when these branches are fetched. Both paths of selected branches are executed but only the correct path commits. In this thesis we propose an architecture to execute multiple paths of selected branches. Branches are selected based on the size and other conditions. Simple and complex branches can be dynamically predicated without requiring a special instruction set nor special compiler optimizations. Furthermore, a technique to reduce part of the overhead generated by the execution of multiple paths is proposed. The performance achieved reaches levels of up to 12% when comparing a Local predictor used in DCE against a Global predictor used in the reference machine. When both machines use a Local predictor, the speedup is increased by an average of 3-3.5%.

A Execução Condicional Dinâmica (DCE) é uma alternativa para redução dos custos relacionados a desvios previstos incorretamente. A idéia básica é buscar todos os fluxos produzidos por um desvio que obedecem algumas restrições relativas à complexidade e tamanho. Como conseqüência, um número menor de previsões é executado, e assim, um número mais baixo de desvios é incorretamente previsto. Contudo, tal como outras soluções multi-fluxo, o DCE requer uma estrutura de controle mais complexa. Na arquitetura DCE, é observado que várias réplicas da mesma instrução são despachadas para as unidades funcionais, bloqueando recursos que poderiam ser utilizados por outras instruções. Essas réplicas são geradas após o ponto de convergência dos diversos fluxos em execução e são necessárias para garantir a semântica correta entre instruções dependentes de dados. Além disso, o DCE continua produzindo réplicas até que o desvio que gerou os fluxos seja resolvido. Assim, uma seção completa do código pode ser replicado, reduzindo o desempenho. Uma alternativa natural para esse problema é reusar essas seções (ou traços) que são replicadas. O objetivo desse trabalho é analisar e avaliar a efetividade do reuso de valores na arquitetura DCE. Como será apresentado, o princípio do reuso, em diferentes granularidades, pode reduzir efetivamente o problema das réplicas e levar a aumentos de desempenho. / The Dynamic Conditional Execution (DCE) is an alternative to reduce the cost of mispredicted branches. The basic idea is to fetch all paths produced by a branch that obey certain restrictions regarding complexity and size. As a consequence, a smaller number of predictions is performed, and therefore, a lower number branches is mispredicted. Nevertheless, as other multipath solutions, DCE requires a more complex control engine. In a DCE architecture, one may observe that several replicas of the same instruction are dispatched to the functional units, blocking resources that might be used by other instructions. Those replicas are produced after the join point of the paths and are required to guarantee the correct semantic among data dependent instructions. Moreover, DCE continues producing replicas until the branch that generated the paths is resolved. Thus, a whole section of code may be replicated, harming performance. A natural alternative to this problem is the attempt to reuse those replicated sections, namely the replicated traces. The goal of this work is to analyze and evaluate the effectiveness of value reuse in DCE architecture. As it will be presented, the principIe of reuse, in different granularities, can reduce effectively the replica problem and lead to performance improvements.

Esta tese apresenta DCE, ou Execução Dinâmica Condicional, como uma alternativa para reduzir o custo da previsão incorreta de desvios. A idéia básica do modelo apresentado é buscar e executar todos os caminhos de desvios que obedecem à certas restrições no que diz respeito a complexidade e tamanho. Como resultado, tem-se um número menor de desvios sendo previstos e consequentemente um número menor de desvios previstos incorretamente. DCE busca todos os caminhos dos desvios selecionados evitando quebras no fluxo de busca quando estes desvios são buscados. Os caminhos buscados dos desvios selecionados são então executados mas somente o caminho correto é completado. Nesta tese nós propomos uma arquitetura para executar múltiplos caminhos dos desvios selecionados. A seleção dos desvios ocorre baseada no tamanho do desvio e em outras condições. A seleção de desvios simples e complexos permite a predicação dinâmica destes desvios sem a necessidade da existência de um conjunto específico de instruções nem otimizações especiais por parte do compilador. Além disso, é proposta também uma técnica para reduzir a sobrecarga gerada pela execução dos múltiplos caminhos dos desvios selecionados. O desempenho alcançado atinge níveis de até 12% quando um previsor de desvios Local é usado no DCE e um previsor Global é usado na máquina de referência. Quando ambas as máquinas empregam previsão Local, há um aumento de desempenho da ordem de 3-3.5%. / This thesis presents DCE, or Dynamic Conditional Execution, as an alternative to reduce the cost of mispredicted branches. The basic idea is to fetch all paths produced by a branch that obey certain restrictions regarding complexity and size. As a result, a smaller number of predictions is performed, and therefore, a lesser number of branches are mispredicted. DCE fetches through selected branches avoiding disruptions in the fetch flow when these branches are fetched. Both paths of selected branches are executed but only the correct path commits. In this thesis we propose an architecture to execute multiple paths of selected branches. Branches are selected based on the size and other conditions. Simple and complex branches can be dynamically predicated without requiring a special instruction set nor special compiler optimizations. Furthermore, a technique to reduce part of the overhead generated by the execution of multiple paths is proposed. The performance achieved reaches levels of up to 12% when comparing a Local predictor used in DCE against a Global predictor used in the reference machine. When both machines use a Local predictor, the speedup is increased by an average of 3-3.5%.

A Execução Condicional Dinâmica (DCE) é uma alternativa para redução dos custos relacionados a desvios previstos incorretamente. A idéia básica é buscar todos os fluxos produzidos por um desvio que obedecem algumas restrições relativas à complexidade e tamanho. Como conseqüência, um número menor de previsões é executado, e assim, um número mais baixo de desvios é incorretamente previsto. Contudo, tal como outras soluções multi-fluxo, o DCE requer uma estrutura de controle mais complexa. Na arquitetura DCE, é observado que várias réplicas da mesma instrução são despachadas para as unidades funcionais, bloqueando recursos que poderiam ser utilizados por outras instruções. Essas réplicas são geradas após o ponto de convergência dos diversos fluxos em execução e são necessárias para garantir a semântica correta entre instruções dependentes de dados. Além disso, o DCE continua produzindo réplicas até que o desvio que gerou os fluxos seja resolvido. Assim, uma seção completa do código pode ser replicado, reduzindo o desempenho. Uma alternativa natural para esse problema é reusar essas seções (ou traços) que são replicadas. O objetivo desse trabalho é analisar e avaliar a efetividade do reuso de valores na arquitetura DCE. Como será apresentado, o princípio do reuso, em diferentes granularidades, pode reduzir efetivamente o problema das réplicas e levar a aumentos de desempenho. / The Dynamic Conditional Execution (DCE) is an alternative to reduce the cost of mispredicted branches. The basic idea is to fetch all paths produced by a branch that obey certain restrictions regarding complexity and size. As a consequence, a smaller number of predictions is performed, and therefore, a lower number branches is mispredicted. Nevertheless, as other multipath solutions, DCE requires a more complex control engine. In a DCE architecture, one may observe that several replicas of the same instruction are dispatched to the functional units, blocking resources that might be used by other instructions. Those replicas are produced after the join point of the paths and are required to guarantee the correct semantic among data dependent instructions. Moreover, DCE continues producing replicas until the branch that generated the paths is resolved. Thus, a whole section of code may be replicated, harming performance. A natural alternative to this problem is the attempt to reuse those replicated sections, namely the replicated traces. The goal of this work is to analyze and evaluate the effectiveness of value reuse in DCE architecture. As it will be presented, the principIe of reuse, in different granularities, can reduce effectively the replica problem and lead to performance improvements.

O sistema de execução forçada é o instrumento previsto no Código de Processo Civil Brasileiro destinado a satisfazer o credor de obrigações pecuniárias contidas em sentenças ou em títulos executivos extrajudiciais. Trata-se de sistema cujo bom funcionamento não só interessa às partes de um litígio, mas a toda sociedade, em função de suas importantes repercussões sociais e econômicas. Por meio da execução forçada o Juiz invade o patrimônio do devedor, independentemente da vontade deste, e expropria bens em benefício do credor. Para o adequado funcionamento da execução forçada é essencial que o ato processual de penhora de bens do devedor seja efetivo. A penhora consiste em apreender e afetar juridicamente bens do devedor, os quais ficam vinculados ao Juízo da execução até o momento próprio de realização da expropriação dos bens. A penhora é ato processual que incide sobre a realidade econômica e social e padece de suas contingências. O objetivo desta dissertação de Mestrado é investigar a relação entre o ato de penhora e seu objeto, a partir da premissa de que o método ou a forma de apreensão judicial deve estar plenamente adaptado aos atributos sociais, jurídicos e econômicos do bem que se pretende apreender. Nesse contexto, será investigado o regime da penhora do Código de Processo Civil Brasileiro, bem como serão estudados os tipos de penhora de bens de significação econômica mais importante na realidade atual. / The system of forced execution is the instrument set forth in the Brazilian Code of Civil Procedure destined to satisfy the creditor of pecuniary obligations contained in judgments or in extrajudicial execution instruments. It is a system, the good functioning of which is of interest not only to the parties in a litigation, but also to society as a whole, in view of its important social and economic repercussions. The Judge, by means of the forced execution, invades the debtors assets, irrespective of the will of the latter, and expropriates assets to the benefit of the creditor. For the proper functioning of the forced execution, it is essential that the procedural act of levy of the debtors assets be effective. The levy consists of seizing and legally affecting the debtors assets, which become bound to the Court of the execution until the specific time of performance of the expropriation of the assets. The levy is a procedural act which applies to economic and social reality, and lacks its contingencies. The objective of this Masters dissertation is to investigate the relationship between the act of levy and its object, starting from the premise that the method or the form of judicial seizure must be fully adapted to the social, juridical and economic attributes of the asset which is intended to be seized. In this context, the regime of levy in the Brazilian Code of Civil Procedure will be investigated, as well studying the types of levy of assets of the most important economic significance in the current reality.